Google is to introduce a new service to its AdWords advertisement management service in April that allows clients to block certain users from seeing their ads. The move will allow advertisers to further combat click fraud, a phenomenon in which website operators click on ads on their own websites to boost revenues, or click on online ads for their competitors to deplete their marketing budgets.

Controlling who is presented with the advertisements allows a company to prevent them from being seen by competitors. Click fraud is considered the Achilles heel of pay-per-click advertising. When advertisers are no longer able to rely on the accuracy of the billing system, they are likely to lose faith in the service.